Brendan Marrocco showed off a few things at his John Hopkins Hospital press conference Tuesday. Most of the attention, of course, was on his newly transplanted arms: Marrocco, a U.S. infantryman, lost all four limbs to a roadside bomb in Iraq in 2009. His double-arm transplant, performed last month, is one of only few ever attempted in the U.S.

But while his new limbs were the stars, the veteran’s beige shirt — bearing the catchphrase “Keep Calm and Chive On” — sent a message to the military community that Marrocco, 26, had also kept his sense of humor.

The T-shirt is from theCHIVE, an entertainment website that scours the internet for funny photos. But unlike many viral photo sites theCHIVE has a surprisingly noble side. Chive Charities, a nonprofit fundraising offshoot, encourages the site’s online community to support orphaned causes. It’s hugely popular with members of the military, co-founder Leo Resig told TIME.

“I’d say theCHIVE is the unofficial site of the U.S. military,” Resig says. “I’ve never met anyone in the military who doesn’t like and frequent theCHIVE.”

They also give away free shirts to firefighters and service personnel like Marrocco. Resig, who co-founded theCHIVE with his brother in 2008, told TIME that the site has probably given away more than 5,000 shirts so far. When they first offered free shirts in September, the site’s founders pledged to pay all production and shipping costs of getting them to the people who needed some laughs the most. They didn’t place a cap on the number they could comp; co-founder John Resig told theCHIVE community they would “lose their shirts on this idea” before they stopped handing them out.

They eventually reached their limit financially, but have remained committed to helping soldiers. Resig says theCHIVE didn’t donate the shirt to Marrocco, but they’ve been in touch with him since Tuesday, when he brought the comedy site to national attention. Resig says he wants to show Marrocco that same support, perhaps through the Chive Charities nonprofit.

“Keep Calm and Chive On is a wink and a nod to millions of people who love theCHIVE,” he says. “It’s his way of saying ‘Hi’ to a lot of people.”

Rebecca Nelson is a writing and web production intern for TIME. Now based in New York, she has lived and reported in Seattle, Chicago, London, Washington, D.C. and Los Angeles. If everything goes as planned, she will graduate from Northwestern University's Medill School of Journalism in June.